Liquid level gauge



Aug. 19, 1952 P. H. BISCOE LIQUID LEVEL GAUGE Filed July 17, 1947 r m e v m Percival H. Biscoe Patented Aug. 19, 1952 LI UID LEVEL GAUGE Percival H. Biscoe, Jacksonville, Fla., assignor to Saf-T-Visi Gauge Corporation, a corporation of Florida Application 1.11117, 1947, serial No. 761,487 1 1 2' Claims.

The present invention relates to improvements in liquid level gauges of the safety sight tube type. u

Conventional liquid; levelgauges usually assume the formofa glass tube mounted between two manually operable cocks which, in turn, are

installed on the walljof the boiler, the arrangementbeing that when the two cocks are open, the level of liquid in the sight tube corresponds to the level of liquid in the boiler."

Notwithstanding their reliability and accuracy,,gauges of this type present considerable disadvantage which results, from accidental breakage of the fragile sight tube. In such event, the contents of the boiler are forcibly blown out through the broken tube, unless immediate steps are taken to close the two cocks of the gauge. This however, is not always a simple v 2 I V the end portions of which are receivable in suitable bores I6 provided in a pair of substantially cylindrical coupling blocks l1. These blocks, in turn,.are provided with externally threaded portions. [8 adaptedto receive compression nuts [9 of conventional type, suitable washers and gaskets 20, 2| respectively being provided in the nuts, whereby the blocks I1 arerigidly secured to the tube 15, as will be clearly apparent.

The free end portions of the blocks I'l constitute what may be referred to as adaptors 22, these being slidably and removably receivable in l the sockets 23 provided in the aforementioned task, particularly if the boiler contains ammonia,

hot water and steam, or the like, in which instances not only is the boiler pressure substantially reduced and considerable amount of material lost, but also, .the' attendant frequently sustains extensive injuries by coming in contact with the hot material while attempting to close the cocks.

One object of the present invention is to provide a new and improved safety liquid level gauge by which some of the shortcomings of the prior art are avoided.

With the above important object in view, and such other objects as may become apparent as this specification proceeds, the invention consists essentially of the arrangement and construction of parts asillustrated in the accompanyin drawings, in which:

Figure 1 is an elevational view of the invention partially broken away and showing the same in situ on a boiler; and

Figure 2 is a longitudinal cross-sectional view of the sight tube assembly per se, illustrated in Figure 1. y

Like characters of reference are used to designate like parts in the specification and throughout the several views.

Referring now to the accompanying drawings in detail, the invention consists of a liquid level gauge designated generally by the reference character 10, the same embodying in its concocks I2, I 3'. The sockets 23 are externally screw-threaded as at 24, and further compression nuts, washers and gaskets 25, 26 and 21 respectively are employed for removably securing the adaptors 22 in the sockets, the nuts 25 engaging the threaded portions 23, as is best shown in Figure 1.

For cleaning purposes, the cook 13 maybe equipped with a suitable drain tap 28; H

Two valve units 29 are provided at the ends of the tube 15, these units being similar in construction, so that a description of one will sufflce for both.

Each of the valve units 29 consists of a screw-' threaded disk 30 secured in the bore [6 adjacent the end of the tube l5 and provided with a central passage or opening 3|, the purpose of which will be hereinafter described. The adaptor 22 terminates in an end wall 32 formed with an additional aperture or passage 33, and the interior of the block defines what may be referred to as a chamber 34. This chamber accommodates a compression spring 35, one end of which bears against the end wall 32, while its remaining end engages a spherical valve member 36. The spring 35 normally urges the member 36 against the disk 30 and the latter, together with the opening 3|, functions as a seat for the member 36. That is to say, the member 36 normally engages the seat, thus closing the passage 3|.

Means are provided for retaining the two valve units 29 in an open position, said means consisting of a collapsible or bendable rod 31 which is disposed longitudinally in the tube Hi.

The end portions of this rod extend through the openings 3| in the disks 30 and engage the valve members 36, as illustrated in Figure 2. It should be understood that the rod 31 is of suflicient length as to retain the valve units 29 in the open position against the resiliency of the springs 35, but it should be noted that the 3 springs, acting through the medium of the members 36, produce a slight arcuation of the rod, so that the mid-portion of the latter is supportably engaged by the inner surface 38 of the tube l5.

It will be apparent from the foregoing that as longas the sight tube [5 remains intact, the rod 31 will retain the valve units 29 in an open position and liquid and gas in the boiler [4 will be permitted to enter the sight tube through the openings 33, 31, so that the level of liquid in the boiler may be easily and accurately determined by simply observing the corresponding level of liquid in the sight tube.

However, if the sight tube [5 is accidentally broken, the resiliency of the springs 35 will cause the rod 3'! to bend or buckle outwardly through the broken tube, and as a result, the valve units 29 will automatically and instantly close, thereby preventing the escape of material from the boiler, even 'while the cooks i=2, 13 remain open.

Attention is particularlydirected 'to the fact that the tube 15 coacts with the rod 31 in retaining the valve units in the open position, inasmuch as the tube prevents the rod from e);- cessive bending, "buckling or collapsing.

After breakage of the tube 15, the entire as- 's'rnbl'y i maybe easily and conveniently replaced by simply closing the cocks i2, l3, unscrewing the nuts 25 and withdrawing the adaptors -2 2 from "the sockets '23.

While in the foregoing there has been shown and described the preferred embodiment of this "invention it is to be understood that minor changes'in'th'e details of construction, combination and arrangement of parts may be resorted 'to Without departing from the spirit and scope 4 of said tube, a valve in each of said blocks, springs normally urging said valves in a closed. position, and a flexible bendable rod disposed longitudinally in said tube, the ends of said rod engaging said valves and retaining the same in an open position against the resiliency of said springs, and said springs acting through the medium of said'valves and urging the mid-portion of saidrod in supportableenga'gement with the inner surface of said tube.

2. A liquid level gauge comprising in combination, a frangible sight tube presenting an inner surface, a coupling block mounted at one end of said tube, means closing the other end of said tube, a valve infsaid block, a spring normally urging said valve in a closed position, and a flexible bendable rod disposed longitudinally in said tube, the ends of said rod engaging said valve and said closing means respectively and retaining said valve in open position against the resiliency of said spring, said spring acting through the medium of saidva'lve urging the mid-portion-of said rod in supportable engagement with "the inner-surface of said tube.

PERCIVAL H. BIS-COE.

CES "GIT-ED The "following references 'are'of record in the file'ofthis patent:

UNITED STATES PATENTS Nurriber Name Date -345I56 Little l July 6, 1886 363,071 Little 'May 17, 1887 952,833 Moore a Mar. 22, 1910 1,224,752 KirKWood May 1, I917 1,253,727 Robinson Jan. '15, I918 361,303 'Brea-k ey '-Dec. 7, 11920 FOREIGN PATENTS Number Country Date 12,715 "'Great'Britain June 30, 1894 :17 ;934 "Great Britain .Dec. :30, I887 

